Automatic valve control mechanisim for tractor mounted loaders



AUTOMATIC VALVE CONTROL MECHANISM 1957 D. M. JARUSESKI ETAL 3,358,860

FOR TRACTOR MOUNTED LOADERS Filed May 11, 1966 I5 Sheets-Sheet 1 w QMK JVJWML/ X INVENTORS DOA/A1. D M JARUSESK/ ADOL PH M SCHL/WA BY 7' 1 ZZZORNEYS Dec. .19, 1967 D. M. JARusEsKl ETAL 3, ,8

AUTOMATIC VALVE CONTROL MECHANISM FOR TRACTOR MOUNTED, LOADERS Filed May 11, 1966 3 Sheets-Sheet 2 I w \I Q 0% a 1 LO Q m \1 INVENTORS DONALD M JA/wsss/r/ ADOLPH SCHL/WA Dec. 19, 1967 5 Sheets-Sheet 5 Filed May 11, 1966 INVENTORS DONALD M JARUSESK/ ADOLPH SCHL/WA United States Patent 3,358,860 AUTOMATIC VALVE CONTROL MECHANISM FOR TRACTOR MOUNTED LOADERS Donald M. Jaruseski, Yorkville, and Adolph M. Schliwa,

Oswego, 11]., assignors to Caterpillar Tractor Co., Peoria, 11]., a corporation of California Filed May 11, 1966, Ser. No. 549,406 4 Claims. (Cl. 214-762) ABSTRACT OF THE DISCLOSURE In a tractor loader, detent means are employed to hold the valve in bucket raising position. Means are also employed to override the detent means and return the valve to neutral position when the bucket reaches a predetermined height. The latter means includes a valve actuating lever, a control rod, and lever means actuating the control rod by the pivotal movement of the jack. Mechanical linkage is employed between the actuating lever and the valve. The control rod actuates means upon raising of the bucket to a predetermined height to bring the control rod into forcible contact with the actuating lever to actuate the same and override the detent means and return the valve to its neutral position.

This invention relates to automatic means for controlling the height to which a loader bucket is raised including detent mechanism for holding a control valve in a position which causes raising of the bucket and automatically releasing the control valve toward a neutral or hold position when the bucket attains a desired height. A somewhat similar means for controlling bucket position is illustrated in our assignees Patent No. 3,155,252 issued to Muellner and Muntjanoff for Adjustable Valve Control Mechanism for Tractor Mounted Loaders. As explained in this patent, the operation of present day earth moving equipment requires operator attention to numerous controls in addition to driving of the tractor upon which the equipmentis mounted. For example in a tractor-mounted loader bucket after the bucket is loaded by'crowding into the material to be handled, it must' be racked back to a carry position by operation of one valve,"then' raised by lift arms which arepivotally attached to the tractor by operation of another valve,

then transported by manipulation of the tractor controls and thereafter dumped, also by operation of a valve. Raising of the bucket requires time and attention of the operator to insure that the motion of the lift arms is stopped when the bucket has attained a proper height. Consequently, operator time and the duration of a complete operating cycle can be shortened by means for automatically discontinuing the raise cycle or stopping the bucket under predetermined height. Another such mechanism is shown for example in our assignees Patent No. 3,211,310 to Robert G. McIndoo for Trip Mechanism for Automatically Positioning Vehicle Loaders.

The mechanism disclosed in the two patents referred to above operate hydraulically and one reason for using hydraulic mechanisms has resulted from the fact that motion of the bucket lift arms has to be sensed and transmitted to the vicinity of control valves at the operators station of the tractor. Consequently most mechanical linkages which may be preferred for their simplicity have been considered impractical because of the necessity of placing mechanical components in a position where they would interfere with access to the operators station.

It is an object of the present invention to provide mechanical means for effecting the referred to automatic the centers of the trunnions control which in no way interferes with access to the operators station.

Another object of the invention is to provide a mechanism with adjustable means to determine the height at which the bucket travel is interrupted but with such means permitting further upward movement under the control of the operator.

A still further object of the invention is to provide the last referred to means, together with an absolute limiting means so that the upward movement beyond the first limiting means will also be limited thus providing a maximum height to which the bucket may be moved.

Still further objects and advantages of the invention and the manner in which it is carried into practice are made apparent in the following description wherein reference is made to the accompanying drawings.

In the drawings:

FIG. 1 is a view in side elevation of a tractor mounted loader bucket having controls constructed in accordance with the present invention;

FIG. 2 is an enlarged fragmentary sectional view illustrating the details of some of the controls shown in FIG. 1;

FIG. 3 is an enlarged detail of anism shown in FIG. 2; and

FIG. 4 is an enlarged fragmentary view illustrating a modified form of a portion of the mechanism illustrated in FIG. 2.

In FIG. 1 a conventional tractor is illustrated as having an operating station 10, an engine compartment 11 and supporting frames, one of which is shown at 12 for mounting the loader bucket 13. The bucket is carried on lift arms 14 pivoted to the frame 12 at 15 and adapted to be raised and lowered by means of a double acting hydraulic jack 16. Tilt linkage, generally indicated at 17, is operated by another double acting jack 18. The lift arms, tilt linkages and jacks are generally provided in pairs, the other members of the pair being disposed on the opposite side of the tractor. The lift jacks 16 which are employed to raise the bucket from the load position illustrated in FIG. 1 to an elevated or carry position are mounted on trunnions as shown at 20 and inraising and lowering of the lift arms the jack Will oscillate about as will also a trunnion band, a portion of which is shown at 21 in FIG. 2.

a portion of the mech- In accordance with the present invention, a bracket 23 is fixed to the trunnion band and will oscillate with the cylinder. Such oscillation of the bracket 23 imparts reciprocal movement to a connecting link 24 which is pivotally connected between the bracket and bellcrank 25 disposed beneath the control console which is shown at 26 in FIGS. 1 and 2. The other end of the bellcrank 25 is pivotally connected with an automatic control rod 28, the function of which will presently be disclosed. An advantage of the arrangement thus far described resides in the fact that a very simple mechanical linkage between the lift jack and a position below the control console is disposed entirely beneath the floor at the operators station. One of the levers in the control console is shown at 30 as connected by mechanical linkage to a lift jack control valve 31. This is a spool valve of conventional construction which is urged by a centering spring (not shown) to a neutral or hold position in which communication with both ends of the lift jack 16 is closed, holding the loader bucket in the position to which it has been adjusted. Raising of the lift arms is accomplished by movement of the control lever 30 to the broken line position shown in FIG. 2. Through a link 32, a lever 33 and link 34, this movement of the control lever imparts rocking motion to a bellcrank 35 in a clockwise direction. This actuates the spool of the valve 31 toward the left by means of a rod 39. This directs fluid under pressure in a well known manner to the head end of the jack 16 extending the jack and imparting raising movement to the lift arms. I

A detent mechanism holds the valve 31 in a lift position and includes a pivoted lever 36 with a roller 37 thereon urged downwardly as by a spring 38. The roller 37 bears against the end of an arm 40 which is carried by the bellcrank 35 and rides over the upper edge of this arm when the bellcrank has been moved in a clockwise direction to prevent return movement of the bellcrank and thus hold the valve in its lift position. The effect of this detent is overcome by the automatic control rod 28, best shown in FIG. 2 as urged toward the left by a spring 42 and guided between a roller 43 and guide finger 44 on a lever 45 pivoted as at 46 to the console housing. The control rod 28 is illustrated in the position occupied when the bucket is lowered. As the bucket is raised, the control rod is moved downwardly by the linkage previously described until an inclined surface 47 thereon registers with the roller 43 and permits the control rod to move toward the left. At this time, the upper end of the control rod engages a depending arm 49 on the control lever 30 and swings the lever toward the hold position, the force of spring 42 overcoming the force of the detent spring 38. Thus the raising movement of the bucket lift arms is discontinued at a predetermined point. This point is established by the position of the roller 43 and may be varied by adjustment of this position which is accomplished as shown in FIG. 3 by fixing the lever 45 with a bolt 50 extending through slot 51 in the wall of the console 26. The nut of the bolt, shown in dotted lines is positioned externally of the console so that it may be loosened to permit raising and lowering of the lever 45 at will.

Generally, the limit just set for the bucket position is somewhat below a maximum height and with the mechanism of the present invention the maximum height can still be obtained by the operator manually holding the control lever 30 in its lift position. As soon as the lever is again released, the spring 42 will be efiective to force it back to its hold position.

A modified form of control mechanism as shown in FIG. 4 wherein the bellcrank 25' corresponds to the bellcrank 25 of FIG. 2 and an automatic control rod 28' performs the function of the rod 28 of FIG. 2 in a different manner. At the upper end of the rod 28' are a pair of adjustably positioned cams 55 and 6 secured to the rod by bolts extending through a slot 57. A link 58 is pivotally connected to a bracket 59 on the console housing and has a slotted end embracing a pin 60' on the rod 28'. A spring 62 urges the rod toward the left and upon clockwise movement of bellcrank 25, the rod is drawn downwardly and the cam 56 engages a roller 64 carried by the control lever extension 49' and swings the control lever toward its hold position. If the operator manipulates the control lever 30 to overcome this release mechanism and to raise the bucket to its maximum position, he will overcome the force of spring 62 permitting the roller 64 to pass cam 56. Upon continued upward movement of the bucket, the cam will move downwardly and again urge the control lever 30 to its hold position when it attains its maximum height.

We claim:

1. In a tractor mounted loader having a bucket supported on lift arms and adapted to be raised by a hydraulic jack pivotally connected to the tractor, a valve for directing fluid to said jack upon movement of the valve away from a neutral position to raise the bucket, detent means to hold the valve in its bucket-raising position, and means to override the detent means and return the valve to its neutral position when the bucket reached a predetermined height, said last named means including a valve actuating lever, a control rod, means actuating said control rod by the pivotal movement of said jack, mechanical linkage between said actuating lever and said valve, and means operable by the actuation of said control rod upon raising of the bucket to a predetermined height to bring the control rod into forcible contact with the actuating lever to actuate the same and override the detent means and return the valve to its neutral position to hold said bucket at said predetermined height.

2. The combination of claim 1 in which the lift jack is trunnion and extends toward the control rod, and mechanical linkage connecting said connecting rod to said control rod for operating the same.

3. The combination of claim 1 which means to adjust the detent overriding means.

4. The combination of claim 1 with means to permit manual movement of the valve toward bucket-raise position to prevent operation of the detent override means.

References Cited UNITED STATES PATENTS 3,045,845 7/1962 Hackett et a1. 214-761 3,141,562. 7/1964 McAdams 2l4-762 3,161,307 12/1964 Schick et al. 214764 3,204,794 9/ 1965 Washbond 214762 HUGO O. SCHULZ, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,358,860 December 19, 1967 Donald M. Jaruseski et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 37, for "which" read with Signed and sealed this 28th day of January 1969.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Ir.

Commissioner of Patents Attesting Officer 

1. IN A TRACTOR MOUNTED LOADER HAVING A BUCKET SUPPORTED ON LIFT ARMS AND ADAPTED TO BE RAISED BY A HYDRAULIC JACK PIVOTALLY CONNECTED TO THE TRACTOR, A VALVE FOR DIRECTING FLUID TO SAID JACK UPON MOVEMENT OF THE VALVE AWAY FROM A NEUTRAL POSITION TO RAISE THE BUCKET, DETENT MEANS TO HOLD THE VALVE IN ITS BUCKET-RAISING POSITION, AND MEANS TO OVERRIDE THE DETENT MEANS AND RETURN THE VALVE TO ITS NEUTRAL POSITION WHEN THE BUCKET REACHED A PREDETERMINED HEIGHT, SAID LAST NAMED MEANS INCLUDING A VALVE ATUATING LEVER, A CONTROL ROD, MEANS ACTUATING SAID CONTROL ROD BY THE PIVOTAL MOVEMENT OF SAID JACK, MECHANICAL LINKAGE BETWEEN SAID ACTUATING LEVER AND SAID VALVE, AND MEANS OPERABLE BY THE ACTUATION OF SAID CONTROL ROD UPON RAISING OF THE BUCKET TO A PREDETERMINED HEIGHT TO BRING THE CONTROL ROD INTO FORCIBLE CONTACT WITH THE ACTUATING LEVER TO ACTUATE THE SAME AND OVERRIDE THE DETENT MEANS AND RETURN THE VALVE TO ITS NEUTRAL POSITION TO HOLD SAID BUCKET AT SAID PREDETERMINED HEIGHT. 